Well screen



@ctt. Q, 1934. A. J. DIEPENBROCK WELL SCREEN Filed May 2, 1955 ATTORNEY.

Patented met. 9, 1934 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to well screen for oil wells and the like, ofthat type wherein perforated pipe is surrounded by vertically spacedannuli forming a series of narrow apertures therebetween, cooperatingwith the perforated pipe for excluding sand and other solids whilepermitting the free flow of oil into the pipe.

It is the object of the invention to arrange the surrounding annuli soas to form apertures of the desired restricted width, and when thescreen is subjected to usual corrosion and wear such as may completelydestroy certain of the annuli, to maintain the restricted spacing of theundamaged annuli and thus insure screening action throughout the entireundamaged area.

More particularly it is the object of the invention to construct thesurrounding annuli as a series of independent rings adapted forsuperimposed assembly on the perforated pipe and hav- 29 ing means forlongitudinally spacing the rings to form the desired restrictedapertures therebetween, and also having means for slightly radiallyspacing the rings from the perforated pipe so that the oil, afterpassing through the restricted apertures and with sand and solidsexcluded, may freely enter the perforations in the pipe.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawing, in which:

Fig. 1 is a side elevation of well screen constructed in accordance withthe invention and showing the screening annuli partly broken away.

Fig. 2 is a transverse section on the line 2-2 of Fig. 1.

Figs. 3 and 4 are detailed sections on the lines 3-3 and 4-4respectively of Fig. 2.

The well screen comprises a usual string of pipe which may include aplurality of pipe lengths 1 connected by usual couplings 2, with thepipe lengths perforated in usual manner. In the present instance theperforations are shown as elongated slots 3. A plurality of annulisurround the pipe 1 and are vertically spaced to form restrictedscreening apertures therebetween; and the invention provides formounting the annuli so that they do not depend upon the tension of acontinuous wrapping for maintaining their spaced assembly, but compriseindependent rings held in place by being supported upon one another inrestricted spaced relation. Consequently the rings are notcircumferentially tensioned, and therefore there is no possibility ofthe spacing of the annuli varying responsve to loss of tension as is thecase with a continuous wire wrapping, and in the event of corrosion orwear severing one or more of the rings, the undamaged rings maintain thesame spaced relation and the screening action is continued throughouttheir area, rather than loosening the entire screen and destroying thescreening action throughout its entire area, as is the case when acontinuous wire wrapping is employed.

The rings comprising the screening annuli are shown at 4, and areindependent of one another and adapted for reception on pipe 1 inslightly 65 radially spaced relation from the perforated pipe as shownat Fig. 2, with the rings preferably relatively narrow as shown at Fig.1 and supported one upon another in slightly longitudinally spacedrelation so as to form restricted annular apertures between the rings.For this purpose the rings have circumferentially spaced longitudinallugs 5 adapted for longitudinal abutment for spacing the superimposedrings, and also have circumferentially spaced longitudinally andradially inwardly projecting lugs 6 adapted for longitudinal abutmentfor maintaining the vertical spacing of the rings, and adapted forradial abutment against the perforated pipe for slightly radiallyspacing the rings from the pipe. The lugs 6 of each ring are appreciablycircumferentially spaced, so that the circumferential spacing ofcircumferentially next adjacent perforations 3 is less than that of nextadjacent lugs of a ring; and more particularly the longitudinallyproximate, circumferentially next adjacent perforations, such as thepair of perforations indicated at Figs.

1 and 2 by the pair of lead lines extending to the reference numeral 3,are circumferentially spaced 9. less distance than that of next adjacentlugs 6 9o of a ring. As a consequence the oil entering between any pairof vertically next adjacent rings, and which is confined betweencircumferentially next adjacent lugs 6 of the rings, is not limited toflow through any one perforation 3, but may flow through at least a pairof circumferentially next adjacent perforations of the vertically spacedrows of perforations.

The rings 4, entirely independent of one another, are assembled on pipe1 in superimposed 10o relation, any number of rings being employed toprovide a screening area completely overlying the perforated area of thepipe; and the rings may be secured in assembled relation by retainingcollars 7 at the respective ends of the series of rings, which may befixed to pipe 1 by welding as shown at '7 The rings are thus securelyheld in place, with uniformly restricted apertures maintained betweenthe rings by the longitudinal alinement and abutment of both the lugs 5and 6. The series of rings may then be additionally secured in desiredassembled relation, by longitudinally welding the series of rings asshown at 8.

The restricted apertures between the rings preferably flare inwardly forfree passage of oil and exclusion of solids such as sand; and for thispurpose the rings may be trapezoids in cross-section as shown at Figs. 3and 4, forming upper and lower beveled surfaces on the rings. Each lug 6preferably projects upwardly from the upper beveled surface of its ringas shown at 6 so as to form a horizontal abutment surface in the planeof the uper edge of the outer periphery of the ring, and as shown at 6each lug depends from its ring such distance as to provide the desiredrestricted apertures between the superimposed rings, and forms ahorizontal abutment surface at its lower end adapted to engage thehorizontal abutment surface of the projection 6 of the next lower ring.The lug also projects radially inwardly from ring 4 as shown at 6, so asto form an abutment surfaceadapted to engage pipe 1 for slightlyradially spacing the rings from the per forated pipe, so as to providefor free flow of oil to the perforations 3 after passing through therestricted flaring apertures between the rings. The lugs 5 have upperand lower projections 5*-5 similar to the projections 6*6 and forminghorizontal abutment surfaces adapted for engagement of the lowerabutment surface of projection 5 with the upper abutment surface of theprojecton 5 of the next lower ring when the screen is operativelyassembled; but the lugs 5 terminate at the inner peripheries of rings 4as shown at Fig. 4, so that the annular space between the rings and theperforated pipe is circumferentially obstructed at only the lugs 6.

The invention thus provides for surrounding perforated pipe with aplurality of annuli which are securely held in restricted longitudinallyspaced relation, slightly radially spaced from the perforated pipe; withthe annuli comprising independent rings held in place by their supportupon one another and without relying upon the tension of a wirewrapping. It will thus be seen that the restricted longitudinal spacingof the annuli is not affected by loss of tension nor by the completewearing away of one or more of the annuli, since even in this lattercontingency the undamaged rings are maintained in the samelongitudinally spaced relation so as to continue the same screeningaction throughout their area.

I claim:

1. In well screen for a perforated pipe, a series of rings adapted formounting on the perforated pipe, circumferentially spaced lugs on therings for radially spacing the r s from the pipe, the

circumferential spacing of next adjacent lugs of each ring being greaterthan that of circumferentially next adjacent perforations of the pipe,and means for supporting the rings in superimposed restricted spacedrelation.

2. In well screen for a perforated pipe, a series of rings adapted forseparate mounting on the perforated pipe, and circumferentially spacedlugs projecting from an end of each ring and adapted to engage a nextadjacent ring for supporting the rings in superimposed restricted spacedrelation, certain of the lugs of each ring projecting radially inwardlyand adapted to engage the perforated pipe for radially spacing the ringsfrom the pipe.

3. In a well screen for a perforated pipe, a series of annuli adapted toencircle the perforated pipe, circumferentially spaced lugs on theannuli for radially spacing said annuli from the pipe, thecircumferential spacing of next adjacent lugs of each annuli beinggreater than that of circumferentially next adjacent perforations of thepipe, and means for supporting the annuli in superimposed restrictedspaced relation.

4. In a well screen for a perforated pipe, a series of annuli adapted toencircle the perforated pipe, circumferentially spaced lugs on theannuli for radially spacing said annuli from the pipe, thecircumferential spacing of next adjacent lugs of each annuli beinggreater than that of longitudinally proximate, circumferentially nextadjacent perforations of the pipe, and means for supporting the annuliin superimposed restricted spaced relation.

5. In a well screen for a perforated pipe, a series of rings adapted forseparate mounting on the perforated pipe, and circumferentially spacedlugs projecting longitudinally from each ring and adapted to engage anext adjacent ring for supporting the rings in superimposed restrictedspaced relation, said lugs also projecting radially inwardly and adaptedto engage the perforated pipe for radially spacing the rings from thepipe.

6. In a Well screen for a perforated pipe, a series of rings adapted forseparate mounting on the perforated pipe, and circumferentially spacedlugs projecting longitudinally from each ring and adapted to engage anext adjacent ring for supporting the rings in superimposed restrictedspaced relation, said lugs also projecting radially inwardly and adaptedto engage the perforated pipe for radially spacing the rings from thepipe, the circumferential spacing of next adjacent lugs of each ringbeing greater than that of circumferentially next adjacent perforationsof the pipe.

ALEX J. DIEPENBROCK.

